Two qubits can be entangled in two distinct temperature regions Export

@misc{citeulike:697539, abstract = {We present an example of a two-qubit Hamiltonian such that the canonical-ensemble thermal state is entangled in two distinct temperature regions. This example is in contrast to an expectation expressed in [O. Osenda and G. A. Raggio, Phys. Rev. A 72, 064102 (2005)] and demonstrates that for two-qubits where thermal entanglement is possible, the qualitative behavior of entanglement as a function of temperature is not simply determined by the ground-state entanglement. Furthermore, we prove a finite bound on the number of possible entangled regions for two qubits, thus showing that arbitrarily many transitions from entanglement to separability are not possible. We also provide an elementary proof that the spectrum of the thermal state at a lower temperature majorizes that at a higher temperature, for any Hamiltonian, and use this result to show that only one entangled region is possible for the special case of Bell-diagonal Hamiltonians.}, archivePrefix = {arXiv}, author = {Berry, Dominic W. and Dowling, Mark R.}, citeulike-article-id = {697539}, citeulike-linkout-0 = {http://arxiv.org/abs/quant-ph/0605176}, citeulike-linkout-1 = {http://arxiv.org/pdf/quant-ph/0605176}, day = {19}, eprint = {quant-ph/0605176}, keywords = {be, can, distinct, entangled, in, qubits, regions, temperature, two}, month = {May}, posted-at = {2006-10-30 10:10:47}, priority = {2}, title = {Two qubits can be entangled in two distinct temperature regions}, url = {http://arxiv.org/abs/quant-ph/0605176}, year = {2006} }

TY - ELEC ID - citeulike:697539 L3 - citeulike-article-id:697539 N2 - We present an example of a two-qubit Hamiltonian such that the canonical-ensemble thermal state is entangled in two distinct temperature regions. This example is in contrast to an expectation expressed in [O. Osenda and G. A. Raggio, Phys. Rev. A 72, 064102 (2005)] and demonstrates that for two-qubits where thermal entanglement is possible, the qualitative behavior of entanglement as a function of temperature is not simply determined by the ground-state entanglement. Furthermore, we prove a finite bound on the number of possible entangled regions for two qubits, thus showing that arbitrarily many transitions from entanglement to separability are not possible. We also provide an elementary proof that the spectrum of the thermal state at a lower temperature majorizes that at a higher temperature, for any Hamiltonian, and use this result to show that only one entangled region is possible for the special case of Bell-diagonal Hamiltonians. TI - Two qubits can be entangled in two distinct temperature regions KW - be KW - can KW - distinct KW - entangled KW - in KW - qubits KW - regions KW - temperature KW - two AU - Berry, Dominic AU - Dowling, Mark PY - 2006/May/19/ UR - http://arxiv.org/abs/quant-ph/0605176 ER -